The present invention relates to a rolling mill stand frame which includes stand frame posts connected by frame cross-piece elements including cross-beams. In particular, the present invention relates to a stand frame of a roller levelling machine for producing sheets, strips and profiles and including top and bottom rolls displaceable relative to each other and which are supported along their length by back-up rolls, which are supported on the cross-beams and are arranged in roll bearers, with the upper cross-beam being adjustable for positioning the levelling rolls.
Multi-part stand frames, which includes housing posts and upper and lower frame cross-piece elements extending between the stand frame posts, for roller levelling machines, as well as for other type of rolling mills and presses are well known. A known stand frame includes two opposite stand frame posts connected by upper and lower cross-beams. In known roller levelling machines, the cross-beams are adjustable up and down with four adjusting cylinders to adjust the gap between the levelling rolls to different thicknesses of levelled stocks, on one side, and, on the other side, to adjust the relative position of the top and bottom levelling rolls in a direction transverse to the movement direction of the levelled stock. The rolling stands are also equipped with adjusting devices which permit adjustment of stand rolls in accordance with the thickness of the rolled sheet or strip.
It is known to provide, for connection of the stand frame posts with the frame cross-piece elements, grooves in which connecting feather keys are arranged. In order to enable taking up forces generated in levellers, presses and rolling mills, providing of several feather key connections is necessary. This is because if a single groove for a feather key is used, it should be formed, in the stand frame post, very deep, and this results in an excessive weakening of the rolling mill housing. Therefore, several feather key connections need be formed and this, however, because of presence of multi-surface arrangements, makes the uniform load distribution very difficult. That is the generated forces cannot be proportionally distributed between separate feather key connections. Also, providing several feather key grooves and feather keys or wedges arranged therein results in a very adverse notch effect.
Accordingly, the object of the invention is providing a stand frame, in particular, for a roller levelling machine for sheets and strips, which would insure a uniform load distribution by using particular connection joints which can be produced with low manufacturing costs.